It probably can because one of them is run over USB. This is not optimal as it requires the video signal to be compressed which will require some CPU time and the picture on the USB monitor may not be perfect for things other than static content, but many people generally are happy with this method of adding a second monitor (not specifically for the rMB, but in general). Might be worth a shot in your case. You could also try a full solution like this. http://www.amazon.com/Plugable-UD-3...450437294&sr=8-3&keywords=usb+docking+station

Pretty much what zhenya says. The MacBook says it can drive an external display natively much greater than 2560x1440. Some of the USB dongles claim that same resolution. It's for you to research and validate.

MacRumors attracts a broad audience
of both consumers and professionals interested in
the latest technologies and products. We also boast an active community focused on
purchasing decisions and technical aspects of the iPhone, iPod, iPad, and Mac platforms.